Source Definition and 1000 Threads

Hey all, question about gravitational potential energy. If an object begins on ground then gains height when it falls then energy it consumes to fall down was the potential created by moving upwards, if an object was created in space, then moves gravitationally towards a celestial body where...

A kid is riding a bike and is ringing bell of 3000 Hz. You are standing still on the sidewalk.When the bicycle moves toward you, you hear a shift in the frequency of the bell. In addition, when the bicycle moves away from you, you hear a different shift in the frequency of the bell. If there is...

I have read that electric field lines of positive source charge end on negative charge and Today I came to know that electric field lines of positive source charge end on infinity,which one is correct?I think electric field lines of positive source charge end on infinity if the positive source...

I have a DC source. then I connect a capacitor from the +ve to ground. if all connection are made from ordinary , copper for example, wires then electrons flow from negative to positive terminals.So electrons from the negative side of the capacitor would flow to the positive. I wonder what...

I'm learning about source coding, and many of the books/resources I've read give examples of the source Xn being defined as a sequence of iid random variables. How about when the sequence is independent but belong to 2 distinct distributions (e.g. Px when Xi is odd, and Px' when Xi is even)...

Hello, I want to calculate the Thevenin/Norton equivalent of a circuit with a dependent current source. I tried to analyse the circuit using loop equations but i don't know how to calculate the voltage drop across the current source. Any help would be appreciated.

I just installed a backup camera on my motor home , which is triggered by the reverse light wire. I would like to add a switch to the circuit so while I'm driving or just to be able to turn on the backup camera (using it as a rear-view mirror) without putting the vehicle in reverse. I probably...

Homework Statement Write the Radiative Transfer Equation for an isotropic incoherent point source a distance p away from a thin lens. Assume that scattering in air can be ignored but absorption cannot be ignored. Homework Equations 1. Radiative Transfer Equation (RTE): \frac{dw}{dt} = \left[...

Hi. Does anyone advise me what I can get out from space and use it as energy for spacecraft ? Thank. By.

Hi, I am trying to implement a low tech, quick "check" source for our radiation thermometers to ensure they are in good working order between calibrations again a calibrated black body radiation source. My idea was to use an integrating sphere with an incandescent lamp as a source. Then two...

Could you tap into the rotational energy of the Earth by transporting water from the equator to the poles? For example, imagine a large "oil" type pipe that went from the equator to the arctic pole, perhaps located submerged in the pacific. Water would initially be pumped into it to generate...

Hello all, The root problem is that I can't put all my analogue inputs onto one input card (each card has 4 inputs) on the project I'm working on. We have four sensors, they should all output 4-20mA. Two are source type outputs, supply voltage goes in, sensor current comes out, current is...

Hello every one umm... I am very new at all of this and I need your help. I have a project that I am working on and it involves a 120V 4.5amp DC concrete drill motor and my bike. I am using this motor because it has enough torque and I just got kinda bored lol anyway, I am having a bit of...

Homework Statement A series RLC circuit is connected to a 60 Hz AC source which produces an amplitude of εmax=20 V. The circuit element values are R= 20 Ω, L= 20 mH, C= 150 μF. Calculate the total impedance of the circuit. Homework Equations Xc=1/ωC XL=ωL Z=√(R^2 +(XL-Xc)^2) tan φ = (XL-Xc)/R...

Homework Statement I am using the 3D implementation of Hooke's law as found in wikipedia at: https://en.wikipedia.org/wiki/Hooke%27s_law I need to find the actual source to cite it in a master's project software write up. Many professors do not consider wikipedia to be an acceptable source...

Hello. I'm in the process of selecting materials for a voltage multiplier. I need to be able to vary a DC voltage source from 0-6kV, possibly with a regulated current up to 20mA...

When experimenting with fusion, why do we always go so big and make extremely expensive reactors that take years to create and even construct facilities for? I've seen some failed attempts at making fusion happen in carbon nanotubes, failing in the sense that the carbon nanotubes are just...

Hi there guys, I'm conducting an experiment to calculate the mass flow rate of water. Bellow is a copy of the procedure: 1) Weigh the mass in kg of a container 2) Connect a flow meter to a tap (any source) with a pipe and insure the departure pipe goes into a sink 3) Open the tap an increase...

I'm extreeeeamly rusty at basic circuit theory. I want to transform a sort of infinite arrangement of this circuit: The values themselves aren't important, just the representation of what's happening, all the verticle resistors are the same value as each other, and all the horizontal resistors...

Hello I'm now studying transmission line theory. I got to know how impedance matching between characteristic impedance of transmission line and electrical load is important to achieve maximum power transfer and minimize power reflection which causes danger for the system. But the textbook...

I am using GNU companion ,in that i am not able to plot random source which i am giving as bytes . how to plot in a sink?

Hello. Let me think about the NPN transistor (Collector-Base-Emitter order). Here base-emitter voltage is forward-biased (The base is higher than the emitter in voltage.) thus current flow of majority carriers (Here they are electrons in N and holes in P) occurs from emitter to base. In next...

Why HE11 mode of corrugated waveguides would not be a natural source of axion field?

If you hit a bound electron with a photon corresponding to that electron's ionization energy, you ionize the electron. What if you hit the electron with a photon with less energy? Will the photon still add its energy to the electron? Will the electron re-emit the photon with less energy? Do you...

The following show the idea how a Thevenin equivalent source is used to replace the primary circuit of transformer. https://www.dropbox.com/s/0kaazx1d1srgirz/reflectedsource.jpg?dl=0 https://www.dropbox.com/s/0kaazx1d1srgirz/reflectedsource.jpg?dl=0 In textbook it is commonly stated that the...

If magnetic charge exists, it can flow. Would the flow of magnetic charge produce a current that would be a source for the curl of B, in Ampere's law? Ever yours Bob Eisenberg Chairman emeritus Dept of Molecular Biophysics Rush University Medical Center

Assume that we are given a big black box with two windows. Each window emits a laser beam. All our best measurement techniques show that the two beams have the same wavelength and have near-perfect mutual coherence (or as good as the self coherence of each output beam). Is it possible to tell...

Hi everybody, As part of my research at UCSD, we are trying to measure Hall resistance of some materials. And to do that we need to send an AC current. So I wondered how we could easily build an ac current source, probably based on op-amp. I know there is the Howland circuit (current pump), but...

Gas pressure in a closed chamber at constant temperature will last forever, unless leaking or chemical reactions occur. Examples are methane in underground gas reservoirs that are hundreds of thousands of years old. Gases stored in bottles. Pressure comes from the gas atoms (with velocity)...

Homework Statement A sound source is placed at the top of a tall (h = 189.6m) radio tower. The source has a frequency of 740 Hz and an amplitude of 19.4 nm at point A. The air surrounding the tower has a density of 1.29 kgm-3 and sound travels through it with a velocity of 343 ms-1. Point A is...

Homework Statement My teacher gave me a method to find Impedance of Thevenin and Norton. Here is her method: she removed Indepentdence source (voltage is closed, current is open) and did not put V external ( so the dependent source did not working because of no source). And she find resistance...

If a fusion reactor could be constructed that runs on Li-7 and hydrogen, and if the energy produced by that reactor where extracted with a direct charging setup, like in a nuclear battery emitting alpha particles, the voltage produced would be the stupendous voltage of 8 mega volts. Now, how do...

Homework Statement Given a series RLC circuit, with one R, one L, and one C element, and an AC voltage source with variable frequency, find the resonant frequency experimentally given an ammeter and a voltmeter. Homework Equations The current in the circuit when the circuit is in resonance is...

industrial quality, water proof with corrosion resistant connectors. something a public aquarium would use. it doesn't matter if their capacitance, resistive or voltage sensing. maybe I should have posted this in the chemistry forum but it doesn't really mater I guess.

Looks like my main pet GR project is about to enter something akin to maintenance mode, since it now does all I currently need it to. It's nothing earth-shattering at first glance, but is very concise (e.g. ~100 lines of Python for the simulator script) and should be easier to understand than...

Consider: ##\nabla^{2} V(\vec{r})= \delta(\vec{r})## By taking the Fourier transform, the differential equation dissapears. Then by transforming that expression back I find something like ##V(r) \sim \frac{1}{r}##. I seem to have lost the homogeneous solutions in this process. Where does this...

(a) Suppose we split a laser into two beams "A" and "B". Is it at all possible to do something to one of the beams, so that, when we bring them back to overlap at the detector(s), they will follow the statistics of two-photon systems? (b) If we use two separate lasers that are phase-locked by...

I would like to to read and process huge CSV files with millions of records, which we collected from the communications carriers' network.Here is my logic as a simplified procedure: 1) Read the CSV file with FTP protocol 2) Parse the CSV file with my own logic, such as combination, duplicates...

hi everyone, nowadays i am working on muon detecting but i need something cheap. i saw on the internet some people are using their smartphone as a detector with sensor or phones cameras. is there anyone can share their code ? there are some samples but they don't share their code.. only can...

Homework Statement It is known that the theoretical resistivity of copper is approximately: 2*10^-8 Ωm. But after I conducted an experiment to find the resistivity of copper, the results turned out to be: 1.68*10^-8Ωm. This is a very small error that can be easily dismissed due to "human...

I have thought for some time that it is physically correct to treat photon source as time evolving rather than photon state (i.e. using Heisenberg picture rather than Schrodinger picture) so I was glad to find this picture in Feynman's book (QED: The Strange Theory of Light and Matter): In...

Hello, I am trying to build a personal (one-manned) propulsion system that will allow individuals to fly above the trees, preferably fast, and for long amounts of time. I plan to do so using propellers. The power will need to be plentiful and long lasting. These are some options that I am...

Hello, I'm currently working on a problem involving the calculation of an unknown voltage source of a circuit containing a resistor, inductor and load in series. Unfortunately, the problem sheet does not give an answer at the end, so I am unsure as to whether my approach is correct -- hence...

kindly help me with a detailed explanation?

Homework Statement Homework Equations V(oc) = I(sc) * R(th) Kirchoff's voltage law The Attempt at a Solution a) is okay. For part b): After redrawing with the R(th) and V(th) found in part a): Equations of loops: s is I(sc) a is I(left loop) left loop: -8 + a(4000) + (a-s)(4000) = 0 right...

Homework Statement Homework Equations V = IR Kirchoff's Voltage Law The Attempt at a Solution [/B] Top loop - a Bottom right - b Bottom left - c Ix = x KVL: top: a(6000) + (a-b)(2000) + 5x - 10=0 bottom right: -5x + (b-a)(2000) + b(3000) + (b-c)(4000) = 0 bottom left ...

Homework Statement Calculate Rs so that the draincurrent ID = 4 mA. Vad does the gain A become? uo/ui? For the transistor: k = 3 mA/V^2 Vt = -2 V also: R1 = 50 k ohm Rd = 2.2 k ohm C = infinity for signalfrequencies image of circuit...

Hi. I'm joining this forum to ask about some equipment I need. At the community college where I teach, we do a lab in freshman physics where students measure the input to and output from a transformer. My AC sources are reaching the end of their lives, so I'm looking for replacements. As far...

This video describes my issue pretty well (I have it set to start when he talks about my specific situation): ETA: looks like the board doesn't allow the video to start at the specific time, the important stuff begins around 5:30 Our applications are a bit different as his design is for...

Homework Statement The current in a series circuit of R=5 ohms and L=30 mH lags the applied voltage by 80 degrees. Determine the source frequency and impedance. (Ans: Z=5+j28.4 , f=150.4 Hz) Homework EquationsThe Attempt at a Solution Current in the inductor, IL = Vm/wL*sin(wt-80) Current...